Question

cos^2y+sinxcosxcosy p=sinycos^2x using u=sinx and v=siny

Answer 1

We can rewrite the equality as:

$(1-v^2)\pm u\sqrt{1-u^2}\sqrt{1-v^2}p=v(1-u^2)$

The sign is chosen depending on the sign of expression $cos\,x\,cos\,y$ .